1. Field of the Invention
This invention relates to reinforcing members suitable for use in rubber composite structures and more particularly to a steel ribbon containing an adhesive coating on the surface thereof and characterized by specific mechanical and metallurgical properties.
2. Description of the Prior Art
The use of steel in various geometric configurations for reinforcing rubber articles is well known. Thus U.S. Pat. No. 3,762,145 discloses metallic filaments twisted together to form a strand. A plurality of these strands are then twisted together thereby forming a cord. Such a technique is well accepted for producing reinforcing members for rubber articles and particularly pneumatic tires. Forming such cords, however, is expensive because of the equipment required and the numerous processing steps involved. Costs are further increased because of low product yields attributed to filament breaks, cord abrasion and other mechanical damage to the cord caused by twisting or stranding. Fatigue resistance is an important property of such reinforcing members and any surface defects which are generally attributed to twisting or stranding may be cause for rejection.
Another technique for reinforcing pneumatic tires is to use reinforcing elements in the form of thin flat strips. Such elements are disclosed in recently issued U.S. Pat. Nos. 3,667,529, 3,794,097 and others dating back to the nineteenth century. In U.S. Pat. No. 3,667,529 flat strips or bands are used in combination with wires or cables to provide reinforcement for radial ply pneumatic tires. In U.S. Pat. No. 3,794,097 flat wires are provided with longitudinally extending grooves in order to enhance adhesion between the ribbon and the rubberized material.